[Scummvm-cvs-logs] SF.net SVN: scummvm: [20884] scummvm/trunk/engines/cine
cyx at users.sourceforge.net
cyx at users.sourceforge.net
Sat Feb 25 10:27:01 CET 2006
Revision: 20884
Author: cyx
Date: 2006-02-25 10:26:16 -0800 (Sat, 25 Feb 2006)
ViewCVS: http://svn.sourceforge.net/scummvm?rev=20884&view=rev
Log Message:
-----------
cleanup unpacking function and get rid of an old hack to prevent buffer overflows.
Modified Paths:
--------------
scummvm/trunk/engines/cine/part.cpp
scummvm/trunk/engines/cine/sfx_player.cpp
scummvm/trunk/engines/cine/unpack.cpp
scummvm/trunk/engines/cine/unpack.h
Modified: scummvm/trunk/engines/cine/part.cpp
===================================================================
--- scummvm/trunk/engines/cine/part.cpp 2006-02-25 18:24:55 UTC (rev 20883)
+++ scummvm/trunk/engines/cine/part.cpp 2006-02-25 18:26:16 UTC (rev 20884)
@@ -203,14 +203,10 @@
if (partBuffer[foundFileIdx].unpackedSize != partBuffer[foundFileIdx].packedSize) {
uint8 *unpackBuffer;
- uint16 realSize;
- unpackBuffer = (uint8 *)malloc(partBuffer[foundFileIdx].packedSize + 500);
+ unpackBuffer = (uint8 *)malloc(partBuffer[foundFileIdx].packedSize);
readFromPart(foundFileIdx, unpackBuffer);
-
- realSize = READ_BE_UINT32(unpackBuffer + partBuffer[foundFileIdx].packedSize - 4);
-
- decomp(unpackBuffer + partBuffer[foundFileIdx].packedSize - 4, dataPtr + realSize, realSize);
+ delphineUnpack(dataPtr, unpackBuffer, partBuffer[foundFileIdx].packedSize);
free(unpackBuffer);
} else {
readFromPart(foundFileIdx, dataPtr);
Modified: scummvm/trunk/engines/cine/sfx_player.cpp
===================================================================
--- scummvm/trunk/engines/cine/sfx_player.cpp 2006-02-25 18:24:55 UTC (rev 20883)
+++ scummvm/trunk/engines/cine/sfx_player.cpp 2006-02-25 18:26:16 UTC (rev 20884)
@@ -117,7 +117,7 @@
if (tempData) {
snd_baseSndFile->seek(be->offset, SEEK_SET);
snd_baseSndFile->read(tempData, be->size);
- decomp(tempData + be->size - 4, entryData + be->unpackedSize, be->unpackedSize);
+ delphineUnpack(entryData, tempData, be->size);
free(tempData);
}
} else {
Modified: scummvm/trunk/engines/cine/unpack.cpp
===================================================================
--- scummvm/trunk/engines/cine/unpack.cpp 2006-02-25 18:24:55 UTC (rev 20883)
+++ scummvm/trunk/engines/cine/unpack.cpp 2006-02-25 18:26:16 UTC (rev 20884)
@@ -26,130 +26,86 @@
namespace Cine {
-uint32 crc; // variable at 5C5A
-uint32 bitbucket; // dx:bx
+static int rcr(UnpackCtx *uc, int CF) {
+ int rCF = (uc->chk & 1);
+ uc->chk >>= 1;
+ if (CF) {
+ uc->chk |= 0x80000000;
+ }
+ return rCF;
+}
-uint16 swap16(uint16 r) {
- return (r >> 8) | (r << 8);
+static int nextChunk(UnpackCtx *uc) {
+ int CF = rcr(uc, 0);
+ if (uc->chk == 0) {
+ uc->chk = READ_BE_UINT32(uc->src); uc->src -= 4;
+ uc->crc ^= uc->chk;
+ CF = rcr(uc, 1);
+ }
+ return CF;
}
-#define loadd(p, d) {\
- d = *(--p);\
- d |= (*(--p)) << 8;\
- d |= (*(--p)) << 16;\
- d |= (*(--p)) << 24;\
+static uint16 getCode(UnpackCtx *uc, uint8 numChunks) {
+ uint16 c = 0;
+ while (numChunks--) {
+ c <<= 1;
+ if (nextChunk(uc)) {
+ c |= 1;
+ }
+ }
+ return c;
}
-#define store(p, b) *(--p) = b
-#define getbit(p, b) { \
- b = bitbucket & 1; \
- bitbucket >>= 1; \
- if (!bitbucket) { \
- loadd(p, bitbucket); \
- crc ^= bitbucket; \
- b = bitbucket & 1; \
- bitbucket >>= 1; \
- bitbucket |= 0x80000000;\
- } \
+
+static void unpackHelper1(UnpackCtx *uc, uint8 numChunks, uint8 addCount) {
+ uint16 count = getCode(uc, numChunks) + addCount + 1;
+ uc->datasize -= count;
+ while (count--) {
+ *uc->dst = (uint8)getCode(uc, 8);
+ --uc->dst;
+ }
}
-#define loadbits(p, b) { \
- b = 0; \
- do { \
- getbit(p, bit); \
- b <<= 1; \
- b |= bit; \
- nbits--; \
- } while (nbits); \
+static void unpackHelper2(UnpackCtx *uc, uint8 numChunks) {
+ uint16 i = getCode(uc, numChunks);
+ uint16 count = uc->size + 1;
+ uc->datasize -= count;
+ while (count--) {
+ *uc->dst = *(uc->dst + i);
+ --uc->dst;
+ }
}
-int decomp(uint8 *in, uint8 *out, int size) {
- uint8 bit; // Carry flag
- uint8 nbits; // cl
- uint8 byte = 0; // ch
- uint16 counter; // bp
- uint16 var = 0; // variable at 5C58
- uint16 ptr;
- uint16 flags;
-
- enum {
- DO_COPY,
- DO_UNPACK
- } action;
-
- loadd(in, crc);
- loadd(in, bitbucket);
- crc ^= bitbucket;
-
- do { // 5A4C
- getbit(in, bit);
- if (!bit) { // 5A94
- getbit(in, bit);
- if (!bit) { // 5AC8
- nbits = 3;
- byte = 0;
- action = DO_COPY;
- } else { // 5ACA
- var = 1;
- nbits = 8;
- action = DO_UNPACK;
+bool delphineUnpack(uint8 *dst, const uint8 *src, int len) {
+ UnpackCtx uc;
+ uc.src = src + len - 4;
+ uc.datasize = READ_BE_UINT32(uc.src); uc.src -= 4;
+ uc.dst = dst + uc.datasize - 1;
+ uc.size = 0;
+ uc.crc = READ_BE_UINT32(uc.src); uc.src -= 4;
+ uc.chk = READ_BE_UINT32(uc.src); uc.src -= 4;
+ uc.crc ^= uc.chk;
+ do {
+ if (!nextChunk(&uc)) {
+ uc.size = 1;
+ if (!nextChunk(&uc)) {
+ unpackHelper1(&uc, 3, 0);
+ } else {
+ unpackHelper2(&uc, 8);
}
- } else { // 5B4F
- nbits = 2;
- loadbits(in, flags);
- if (flags < 2) {
- nbits = flags + 9; // 5BC3
- var = flags + 2;
- action = DO_UNPACK;
- } else if (flags == 3) {
- nbits = 8; // 5B4A
- byte = 8;
- action = DO_COPY;
+ } else {
+ uint16 c = getCode(&uc, 2);
+ if (c == 3) {
+ unpackHelper1(&uc, 8, 8);
+ } else if (c < 2) {
+ uc.size = c + 2;
+ unpackHelper2(&uc, c + 9);
} else {
- nbits = 8;
- loadbits(in, var);
- nbits = 12;
- action = DO_UNPACK;
+ uc.size = getCode(&uc, 8);
+ unpackHelper2(&uc, 12);
}
}
-
- switch (action) {
- case DO_COPY:
- {
- // 5AD1
- loadbits(in, counter); // 5AFD
- counter += byte;
- counter++;
- size -= counter;
- do {
- nbits = 8;
- loadbits(in, byte); // 5B3F
- store(out, byte);
- counter--;
- } while (counter); // 5B45
- break;
- }
-
- case DO_UNPACK:
-
- // 5BD3
- loadbits(in, ptr); // 5BFF
- counter = var + 1;
- size -= counter;
- do {
- byte = *(out + ptr - 1);
- store(out, byte);
- counter--;
- } while (counter);
- }
- } while (size > 0);
-
- // 5C32
- // ???
- if (crc) {
- return -1;
- } else {
- return 0;
- }
+ } while (uc.datasize > 0);
+ return uc.crc == 0;
}
} // End of namespace Cine
Modified: scummvm/trunk/engines/cine/unpack.h
===================================================================
--- scummvm/trunk/engines/cine/unpack.h 2006-02-25 18:24:55 UTC (rev 20883)
+++ scummvm/trunk/engines/cine/unpack.h 2006-02-25 18:26:16 UTC (rev 20884)
@@ -30,8 +30,16 @@
namespace Cine {
-int decomp(uint8 *in, uint8 *out, int size);
+struct UnpackCtx {
+ int size, datasize;
+ uint32 crc;
+ uint32 chk;
+ uint8 *dst;
+ const uint8 *src;
+};
+bool delphineUnpack(uint8 *dst, const uint8 *src, int len);
+
} // End of namespace Cine
#endif
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